Computer chip design has improved at a rapid pace. According to Moore""s law, the number of switches which can be produced on a computer chip has doubled every 18 months. Chips now can hold millions, of transistors. However, it is becoming increasingly difficult to increase the number of elements on a chip using present technologies. At the present rate, in the next few years the theoretical limit of silicon based chips will be reached. Since, the data storage and processing capabilities of microchips are determined by the number of elements which can be manufactured on a chip, new technologies are required which will allow for the development of higher performance chips.
Present chip technology is also limiting when wires need to be crossed on a chip. For the most part, the design of a computer chip is limited to two dimensions. Each time a circuit must cross another circuit, another layer must be added to the chip. This increases the cost and decreases the speed of the resulting chip.
A number of alternatives to standard silicon based complementary metal oxide semiconductor (xe2x80x9cCMOSxe2x80x9d) devices have been proposed, including single electron transistors, quantum cellular automata, neural networks, and molecular logic devices. (Chen et al., Appl. Phys. Lett. 68:1954 (1996); Tougaw, et al, J. Appl. Phys. 75:181 (1994); Caldwell, et al., Science 277:93 (1997); Mead, Proc. IEEE 78:1629 (1990); Hopfiled, et al., Science 233:625 (1986); Aviram, et al., Chem. Phys. Lett. 29:277 (1974); and Petty et al. Eds., Introduction to Molecular Electronics (Edward Arnold, London, 1995)). The common goal is to produce logic devices on a nanometer scale. Such dimensions are more commonly associated with molecules than integrated circuits.
DNA molecules has recently been used as a support structure for the formation of 100 nanometer scale silver wires (Braun et al., xe2x80x9cDNA-Templated Assembly and Electrode Attachment of a Conducting Silver Wire,xe2x80x9d Nature 391:775-78 (1998); PCT Application WO 99/04440, which are hereby incorporated by reference). Furthermore, the DNA molecule allows for specific targeting of the end of the DNA-wire to complimentary nucleotide sequences on a chip. The reduced size of these wires allows for a lower level of voltage to be used in a circuit, decreases operating temperatures and magnetic field strength, and faster circuits.
Integrated circuits on computer chips require numerous structures including, resistors, capacitors, and transistors. Therefore, the reduction of wiring to the 100 nanometer level may somewhat reduce the size of integrated circuits but the improvements are limited by the size of the other components.
Nucleic acid molecule directed assembly is also advantageous because it can direct the synthesis of three dimensional structures. Inductors can not be constructed on conventional chips, because they are three dimensional structures. Molecular biology provides tools for manipulating nucleic acid molecules at the molecular level. Nucleic acid molecules also provide other advantages, since nucleic acid molecules can be rapidly replicated with high fidelity using existing technologies. Furthermore, nucleic acid molecules can store information in their structure which can be used to direct the formation of complex circuits.
xe2x80x9cDNA computersxe2x80x9d have also been described recently in the literature in which computation occurs via chemical reactions. (Adelman, Science 266:1021 (1994), which is hereby incorporated by reference). This method has limited usefulness, because the nucleic acid molecules must be synthesized, reacted together, and the appropriate xe2x80x9cresultxe2x80x9d must be isolated and sequenced. Thus, it is unclear how this technology could be used for everyday applications.
Therefore, new methods of fabricating integrated circuit components are needed, where elements of an integrated circuit can be manufactured on a nano scale. Furthermore, a need exists for taking advantage of the information coding capabilities of DNA in the formation of integrated circuits.
The present invention provides a method of masking a region of a nucleic acid molecule by binding a nucleic acid binding molecule to a binding site on the nucleic acid molecule, coating the non-protected portions of the nucleic acid molecule with a material, and removing the nucleic acid binding molecule from the nucleic acid molecule.
A method of manufacturing a nano-scale device using a nucleic acid molecule as a template is also provided by providing a nucleic acid molecule template, protecting a region or regions of the template using a nucleic acid binding molecule, coating the unprotected regions with a first material, removing the nucleic acid binding molecule, and coating the unprotected and uncoated regions of the template with a second material to form a nano-scale device.
A method of manufacturing a circuit element using a nucleic acid molecule as a template is also provided by providing a nucleic acid molecule template, protecting a region or regions of the template using a nucleic acid binding molecule, coating the unprotected regions with a first material, removing the nucleic acid binding molecule, and coating the unprotected and uncoated regions of the template with a second material to form a circuit element, where the second electrically conductive or insulating material is different from the first second electrically conductive or insulating material.
A further embodiment of the present invention is a circuit element having a nucleic acid template where two or more regions of the template are coated with different materials.
The invention also provides a resistor, a capacitor, an inducer, and a transistor each having a nucleic acid molecule template.
Yet another embodiment of the invention is a method of forming a circuit element by applying a semiconductor to a nucleic acid molecule.
Another embodiment of the invention is a circuit element with a nucleic acid template where two or more regions of the template are coated with different materials.
Another embodiment of the invention is a resistor having a first material separated by a second material. The second material has a different resistivity than the first material and the first and second materials having a common nucleic acid template core.
Another embodiment of the invention is a resistor with at least one resistive material and a pair of at least partially conductive leads. Each of the leads is coupled to the resistive material and the resistive material and the pair of leads have a nucleic acid template core.
Yet another embodiment of the invention is a diode with a first type of semiconductor material adjacent to a second type of semiconductor material. The first and second types of semiconductor materials have a common nucleic acid template core.
Yet another embodiment of the invention is a diode with a first type of semiconductor material adjacent to second type of semiconductor material and a pair of at least partially conductive leads. Each of the leads is coupled to one of the first and second types of semiconductor materials and the first and second types of semiconductor materials and the pair of leads have a nucleic acid template core.
A further embodiment of the invention is a capacitor with a pair of at least partially conductive plates separated by a dielectric where each of the plates has a nucleic acid template core.
A further embodiment of the invention is a capacitor with a pair of at least partially conductive plates separated by a dielectric where the dielectric has a nucleic acid template core. Yet another embodiment of the invention is a transistor comprising a first type of semiconductor material separated by a second type of semiconductor material.
The first and second types of semiconductor materials have a common nucleic acid template core.
Yet another embodiment of the invention is transistor with a second type of semiconductor material separating a first type of semiconductor material. Each of a plurality of at least partially conductive leads is coupled to one of the first and second types of semiconductor materials. The first and second types of semiconductor materials and the leads have a nucleic acid template core.
A further embodiment of the invention is an inducer with a coil of at least partially conductive material where the coil has a nucleic acid template core.
Another embodiment of the invention is a method for making a resistor. The method includes: protecting at least one region of a nucleic acid molecule template using a nucleic acid binding molecule; coating unprotected regions of the nucleic acid molecule template with a first conductive material; removing the nucleic acid binding molecule from the protected region; and coating the protected region with a second conductive material, where the second conductive material has a different resistivity from the first conductive material.
Another embodiment of the invention is a method for making a diode. The method includes: protecting at least one region of a nucleic acid molecule template using two or more nucleic acid binding molecules; coating unprotected regions of the nucleic acid molecule template with a conductive material; removing at least one of the nucleic acid binding molecules from a one portion of the protected region; coating the one portion of the protected region with a first-type of semiconductor material; removing any remaining ones of the nucleic acid binding molecules from any remaining portion of the protected region; coating the remaining portion of the protected region with a second type of semiconductor material.
Yet another embodiment of the invention is a method for making a capacitor. The method includes coating parallel regions of a nucleic acid molecule template with a conductive material where each of the coated parallel regions is coupled to a lead.
Yet another embodiment of the present invention is another method for making a capacitor. The method includes: protecting a dielectric region of a nucleic acid molecule template between parallel regions of a nucleic acid molecule template with at least one nucleic acid binding molecule; coating unprotected parallel regions of the nucleic acid molecule template around the dielectric region with a conductive material; removing the nucleic acid binding molecule from the dielectric region; and coating the dielectric region with a dielectric material.
A further embodiment of the invention is a method for making a transistor. The method includes: protecting a central region and two of three adjacent branch regions of a nucleic acid molecule template with nucleic acid binding molecules; coating unprotected regions of the nucleic acid molecule template with a conductive material; removing the one or more nucleic acid binding molecules protecting the central region of the nucleic acid molecule template; coating the central region with a first-type of semiconductor material; removing the nucleic acid binding molecules from the protected branch regions; and coating the branch regions with a second type of semiconductor material.
Yet another embodiment of the invention is a method for making an inducer. The method includes wrapping a nucleic acid molecule template around at least one protein and coating the nucleic acid molecule template with a first conductive material.